Thursday, October 20, 2011

Hints on the Winter Weather Outlook for Cleveland

We use a tossed salad of variables in determining our winter weather outlook. The northern Pacific Ocean, central and tropical Atlantic Ocean offers some great clues as do the tropical patterns that stretch from central Africa over the Indian Ocean eastward over the central Pacific Ocean.  The upper atmosphere over the tropics reveals connections to jet stream position which dictate how variable the cold, arctic intrusions will be over the Great Lakes.  By analyzing these variables from past winters, we come up with the "best match" that  fits the upcoming winter for Cleveland and Northeastern Ohio.

Dividing up the winter into two parts gives a bit more clarity to the winter outlook. 

First November and December and early January:

One of the main drivers of our weather patterns are from ENSO or the changes in the tropical Pacific Ocean sea surface temperatures better known as El Nino (warmer than normal) or La Nina (cooler than normal).

Based on these parameters above, the years that match up fairly well are:


Add up these winters NOVEMBER, DECEMBER AND JANUARY to come up temperatures compared to normal would be:

Andre Bernier has an excellent blog post on the "tricky, harder to predict" variables of winter. These variables all describe changes in the arctic and the north Atlantic which are more random than ENSO. You will notice that in the years these Arctic and north Atlantic factors were the strongest/coldest--early 60s, mid 1970s--(see Andre's first graphic), LA NINAS WERE PRESENT which fits this upcoming winter.  One of the strongest La Nina periods in recent times was the mid 1970s and we all know, if you are from Cleveland, how snowy those winters were!  These "wild cards" will play a significant role in how and when the arctic air pushes south and, early on, when and how much lake effect snow we will receive.

Watch what happens when we ADD the years in the mid 1970s where a weak to strong La Nina persisted with VERY STRONG/COLD ARCTIC patterns which subside in January, February and March:   THOSE WINTERS FEATURED NEAR NORMAL TO SLIGHTLY ABOVE NORMAL TEMPERATURES FOR NORTHERN OHIO!

Let's hope for this weaker arctic pattern to return later this winter with its drier, less cold air in January and February. That should allow for the snow cover to melt which would keep the snow mold from forming on our lawns as it has in recent winters.

Monday, October 17, 2011

Record Rainfall/Drought. Have We Seen This Before?

Please read the maps below as an unbiased reader.

As always, let the data soak in. Let it breathe like a fine scotch. Chew it for a bit. Take it for a ride in your mind. Feel the synapses fire; the serotonin flowing throughout your cerebral cortex. Then and only then, create an opinion based on the data.

This data is from NOAA Earth System Research Laboratory which you can look up at any time.
Its open to the public. Here in Cleveland, we are about to break the all-time rainfall record set back in 1990. So I decided to check the rest of the country's rainfall data as compared with the last 60+ years.

I used the years previous that best fit this year's conditions: Strong-weakening-then-building La Nina, Pacific is in a cold mode (PDO negative) and the Atlantic in a warm mode (AMO is positive).

Plugging in these conditions, we get 4 solid fits. 1918, 1951, 1956 and 2011. (2009 fits but I left it out because the Arctic Oscillation was super-negative and would skew the temperature data way too cold)

Below are the three sets of data I dug up from January to September of each of the 4 years. Precipitation compared to normal, Temperatures compared to normal and the Palmer Drought Index which describes how severe the ground conditions are wet or dry. The LEFT MAP shows PRECIP ANOMALIES.

The RIGHT MAP shows TEMPERATURE ANOMALIES. The BOTTOM MAP shows PALMER DROUGHT INDEX. I've circled the anomalies that are high/low for comparison sake. The purple shows Cleveland.

First 1918...
Now, 1951...
Then 1956...
Finally, this year:
No wonder my tomato plants didn't do well this year. Way too much rain and not enough sustained heat this summer. Just for the heck of it, what was it like in the middle of the Dust Bowl 30s? Here is 1934: The above normal rainfall off of the coast was due to a tropical storm in September. Otherwise, it would have been a very dry year indeed!
As you can see, severe drought in Texas and in the Midwest is frequent in La Nina years with a Cold PDO especially.  

What the media never mentions are these naturally occurring climate teleconnections IN CONJUNCTION WITH human induced global climate change.

While they are not mutually exclusive, naturally occurring teleconnections are well documented going back to the 1880s. I'd like to think that Climate Change is a toss salad of both natural climate cycles/teleconnections and AGW.   

My beef is you only hear about the AGW component. It only reinforces the "science isn't cool" mindset among the general public. Scientists are already viewed as "geeks" and "elitists" completely out of touch with reality. Painting an incomplete scientific picture only makes this notion worse.

Back to the comparison: Could this record-setting rainfall be a harbinger of what is to come for this winter? See my previous post on some hints on January.
The winter weather Outlook is coming on November 3rd!